class_docstr: Base class for subplots, which are :class:`Axes` instances with
  additional methods to facilitate generating and manipulating a set
  of :class:`Axes` within a figure.
code: def __reduce__(self):
      # get the first axes class which does not
      # inherit from a subplotbase
  
      def not_subplotbase(c):
          return issubclass(c, Axes) and not issubclass(c, SubplotBase)
  
      axes_class = [
          c for c in self.__class__.mro() if not_subplotbase(c)
      ][0]
      r = [
          _PicklableSubplotClassConstructor(),
          (axes_class,),
          self.__getstate__(),
      ]
      return tuple(r)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  from six.moves import map
  from matplotlib.gridspec import GridSpec, SubplotSpec
  from matplotlib import docstring
  import matplotlib.artist
  from matplotlib.axes._axes import Axes
  import matplotlib._layoutbox
  import warnings
  from matplotlib.cbook import mplDeprecation
label_desc: Use image node_id 2 for calling the SubplotBase obj's underlying member method code with example usage: obj.__reduce__() and returns: tuple, unknown